1. Field
The present disclosure relates generally to manufacturing vehicles and in particular to manufacturing spacecraft. Still more particularly, the present disclosure relates to a method and apparatus for manufacturing bonded joints for low temperature applications.
2. Background
A spacecraft may be a vehicle designed for space flight. Spacecraft may be used for various purposes, such as, for example, without limitation, communications, earth observation, meteorology, navigation, and other suitable functions. Spacecraft may be reusable. For example, without limitation, a space shuttle is an example of a reusable spacecraft. A launch vehicle may be another form of a spacecraft used to lift another spacecraft into orbit or space.
Both a space shuttle and a launch vehicle may have propulsion systems. These propulsion systems may include various types of propellants such as, for example, without limitation, a solid propellant, a liquid propellant, a mixture of both solid and liquid propellant, and/or any other suitable propellant. Liquid propellants may include, for example, without limitation, liquid hydrogen and/or liquid oxygen. These gases may be stored in liquid form in cryogenic tanks. A cryogenic tank may store and/or maintain liquid propellants at very low temperatures, such as, for example, without limitation, below −238 degrees Fahrenheit.
In a spacecraft or launch vehicle that uses these types of propellants, these tanks may be connected to the structure of the spacecraft using joints. A joint is a location and/or place where a first structure may be attached to a second structure. Y-joints may be used to connect the tanks to the spacecraft structures. It may be desirable to increase the strength of lap joints above current levels. A Y-joint with a softening strip may be used to provide the needed strength.
These types of joints, however, may be subjected to loading that exceeds the strength of simple lap joints. With the use of cryogenic propellants, the joints used to attach the tanks to the spacecraft structure may be subjected to very cold temperatures. Most materials for use as a softening strip may become too stiff at cryogenic temperatures and/or may have a coefficient of thermal expansion that may be incompatible with other joint components. A softening strip may be a component used to reinforce a joint.
Therefore, it would be advantageous to have a method and apparatus that overcomes the problems discussed above.